Concrete mixer



Aprii 1949- L. G. HILKEMEIER 2,467,588

CONCRETE MIXER Filed April 14, 1944 I 4 Sheets-Sheet 1 UM 4. J; 3W

3 LOUIS G. HILKEMEIER,

April 19, 1949. I L.I)G.IHILKEMEIER CONCRETE MIXER 4 Sheets-Sheet 2 Filed April 14, 1944 LOUIS. G. HILKEMEIER,

April 19, 1949; cs. HILKEMEIER CONCRETE MIXER -4 Shets-Sheet 3 Filed April 14, 1944 o a I LOUIS G. HILKEMEIER,

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April 19, 1949.- L. G, HlLKEMEl ER CONCRETE MIXER Filed April 14, 1944 4 Sheets-Sheet 4 W m k m a 3 M E K I H G Q m Q m W L I wm I A 3 R V A n u. S. as A V L 4 I I NY J1. IMWH MN] w m J w W, X x m I Q mm Q W Patented Apr. 19, 1949 CONCRETE MIXER Louis G. Hilkemeier, Milwaukee. Wis., assignor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application April 14, 1944., Serial No. 531,082

6 Claims.

The invention relates to concrete mixers, and has for one of its principal objects the provision of an improved mechanism for eifecting charging of the concrete-making materials into the mixing chamber. While adaptable to various types of mixers, for purposes of the present disclosure it has been illustrated and will be described in connection with a mixer of the truckmounted rotatable drum type, such as is now widely used to effect preparation of concrete mixtures during travel of the machine from a central batching plant to the point at which the mixture is to be used.

A recently developed trailer model of such a machine, adapted for towing by a tractor vehicle rather than traverse under its own power, is illustrated in the accompanying drawings forming a part of this specification, in which like reference characters designate like parts in all the views, and in which:

Figure 1 is a side elevational view of the said machine, equipped with one form of charging apparatus constructed and arranged in accordance with the invention;

Fig. 2 is an end elevational view thereof, as seen from the right of Fig. 1;

Fig. 3 is an enlarged sectional-elevational view of the rear portion of the machine, in general approximately on the plane indicated by the line 3-3 of Fig. 2, looking in the direction of the arrows, and showing the charging bucket or skip in its lowermost and an intermediate position;

Fig. 4 is a view similar to Fig. 3 but taken approximately on the plane indicated by the line 44 of Fig. 2, and showing the parts in the positions assumed when the skip is discharging its batch of raw materials into the mixing drum;

Fig. 5 is a fragmentary top plan view of a portion of the parts shown in Fig. 3;

Fig. 6 is a view similar to Fig. 2 but with parts broken away and omitted to better illustrate the controls for the skip raising and lowering mechanism;

Fig. 7 is a fragmentary side elevational view showing said controls, parts also being broken away and omitted therein;

Fig. 8 is a fragmentary sectional-plan view, taken approximately on the plane indicated by the line 88 of Fig. 7 and Fig. 9 is a longitudinal sectional view of the skip raising and lowering transmission.

The mixer here shown is of the fixed-inclinedaxis high discharge type, and comprises a trailer chassis 10 mounted upon wheels II for ground traverse and provided with a tow-pole l2 for connection to a tractor vehicle whereby it may be drawn over a road. A coniform mixing drum 13, having internal mixing blades of a well known form, is mounted on the said chassis for rotation about a fixedly inclined axis, and is arranged to be driven by a motor contained within a housing :5, by means of a reduction and reversing gear transmission l6 and a chain and sprocket drive ii. A suitable water system including a tank i8 is provided for supplying the requisite water for the mixture to the drum 13. The drum is closed at its forward end, and at its rearward end is provided with a charging and discharging opening l3 surrounded by a drip ring 19 (see Figs. 2, 4, 6 and 7). A discharge chute 20 is fixedly supported by the frame It in co-operative relation to the said opening, for directing the mixed concrete as it is discharged from the drum, which chute may be provided with a hinged extension or sub-chute 2i for extending its range.

The parts thus far described are more or less conventional in this type of machine, and for the most part are or may be essentially similar to or the mechanical equivalents of the corresponding parts disclosed in the-prior U. S. Patent No. 2,045,532 granted June 23, 1936, on an application filed by John C. Merwin et al.

The charging mechanism of the present invention, as here shown comprises an upright guide channel 25 secured to each rear corner of the frame ill, the upper portions of which channels are bent over forwardly, as indicated at 26. A skip or bucket 21, open at its top as at 28 to receive the batches of aggregates, and having a forward discharging opening 29, is provided with forwardly extending arm structures 30 which carry rollers 31 disposed to traverse the guide channels 25. The stub shafts 32 journalling the lower rollers 3! extend through slots 33 formed inthe Webs of.the channels 25, and through engagement with the upper and lower ends of these slots the said shafts limit the upward and downward travel of the skip 21. The stub shafts 32 also carry brackets 35 to which the respective ends of sprocket chains 36 are attached, which chains are trained about upper idler sprockets 31, journaled on stub shafts 38 mounted in brackets 39 secured to the upper portions of the guide channels 25. The chains 36 are also trained about lower driving sprockets 40, carried by a through shaft ll which is driven from a countershaft 42 by a chain and sprocket drive 43. The said countershaft 4'2 is the output shaft of a transmission 35, the input shaft of which is driven by a sprocket chain 46 from a sprocket 44 on the drum l3. The transmission mechanism 45 (to be later described more in detail) may be manually controlled by the operator by means of a lever 41.

One end of the chains 36 may be connected to the chain anchors or brackets 35 by resilient chain tightening devices 52, see Fig. 1.

Bearing brackets 55 are mounted on the forwardly turned upper portions 25 of the guide channels 25, in which brackets is mounted a transverse shaft 56, provided at one end with an operating lever 51 and carrying a pair of arms 58 which are rigidly connected to a charging chute 59. This chute is non-rotatable and nor-.- mally slidably engages with portions of the drip ring l9 surrounding the charging and discharging opening in the rear end of the drum. The chute is preferably provided with any suitable type of sealing ring (not shown) for effecting a tight slidable but separable joint between it and the sealing ring.

To avoid interference with the forward portion of the skip 21 in its upward and downward travel, the chute 59 extends rearwardly only substantially as shown in Figs. 3 and 4, and this leaves a considerable gap when the skip is in its unloading position of Fig. 4, through which gap portions of the material might be spilled in the transfer from the skip to the chute and drum. To prevent such spilling and waste, an extension or apron 60 is provided, here shown as comprising a substantially U-shaped member, the arms Bl of which are pivotally mounted on the transverse shaft 58. This extension or apron normally lies telescoped within the chute 59, as shown in Figs. 3 and 5, but as the skip is elevated toward the unloading position the apron is automatically drawn out thereby to the position shown in Fig. 4, where it sufficiently bridges the gap between the skip and chute to avoid the spilling of the materials.

This automatic outward movement of the apron 69 is accomplished through the medium of projections 62, here shown as constituted by the end portions of a rod 83 rigidly secured along the rearward lip of the apron, which projections are disposed in the path of calm plates 64 carried by the arm structures 30 of the skip. Thus, when the skip reaches the broken line position shown in Fig. 3, the cam plates 64 begin to engage under the projections 62 of the apron, and as the skip continues its movement to its discharging position, the apron is drawn out to its Fig. 4 position, the projections 82 sliding along the said plates 54. After transfer of the materials to the drum is completed, the action is reversed as the skip is lowered, the apron 69 returning to its Fig. 3 position by gravity.

As best shown in Fig. 9, the skip raising and lowering transmission 45 comprises an input shaft It rigidly carrying a sprocket H about which the drive chain 46 is trained. The said shaft also carries a bevel gear 12 which drives a pair of bevel gears 13 and 14 carried respectively by sleeves l and 16 which are journaled in bearings 11 and 18 carried by the end plates 19 and 89 of the housing 8!. The countershaft 42 is journaled in the sleeves l5 and Hi and has splined to it the driven element 83 of a friction clutch 84, the driving element 85 of which is car--v ried by the sleeve 15. As here shown, the clutch 84 is of the multiple disk type and includes a presser ring 86 for pressing the disks into power transmitting engagement, which ring is actuated by toggle linkage 81 operable by a shifting col ar,

88 slidably mounted on the shaft 42. The said linkage is preferably of the well known selflocking type whereby, when the clutch is shifted into engagement, it will be held there until the toggle is broken through positive movement of the collar 88 in the opposite direction. Th reciprocating movements of the said collar are effected by a shifting yoke 89, pivoted on the frame of the machine.

The shaft 42 also rigidly carries the output sprocket 90 about which is trained the chain 43 which drives the shaft 4|. The hub 9| of this sprocket has secured to it a brake drum element 92, with which a brake band 93 is operatively associated. The brake drum element is provided with a clutch facing 94 which is adapted to be brought into and out of engagement with a clutch member 95 carried by the sleeve 15. Since engagement of this clutch as well as engagement of the clutch 84 each tends to drive the shaft 42, and since the gears 13 and 14 (which through their sleeves l5 and I6 drive the driving elements 85 and 95 of the respective clutches) are rotated in opposite directions by the gear 12, the parts are so constructed and arranged that the two clutches maybe alternately but not simultaneously engaged.

Engagement of the clutch elements 94 and 95 is secured through slight endwise movement of the shaft 42, toward the left as viewed in Fig. 9, in its journals in the sleeves I5 and 16, and is effected by engagement of the end face of the shifting collar 88 with an abutment on the shaft provided by a disk or plate 96 secured to the end of said shaft, and one or more washers 91. Sinc movement of the collar 88 toward the left from the position shown in Fig. 9 breaks the toggle lock provided by the linkage 81, the clutch 84 will be disengaged before the clutch element 94 is brought into engagement with the element 9.5. On the other hand, movement of the collar 88 toward the right to disengage it from the abutment 96, 9'! permits disengagement of the clutch elements 94, 95 before the elements of the clutch 84 are brought into engagement. There is of course a neutral point at which neither clutch is engaged, and at this time the brake band 93 is engaged with the brake drum 92 by a spring to restrain movement of the shaft 42 and the parts driven thereby. This restraint however, is released upon movement of the controls to engage either clutch.

The clutch 84 is the main clutch of the skip operating mechanism, and it is through its engagement that the skip is elevated to the Fig. 4 position. The clutch 94, 95 on the other hand, is engaged during descent of the skip from said position, and it may perform two functions. First, should the skip tend to stick or hang in the elevated position, engagement of this latter clutch .Dplies power to the skip operating mechanism tending to draw the skip down; and second, the skip is coupled to the drum (and engine) during descent whereby its lowering movement is effectively retarded and controlled without relying upon the brake 92, 93. .That is to say, the gravitational tendency of theskip to descend rapidly is absorbed in driving the drum (and engine) and its lowering movements are therefore at a uniform and reasonable rate of speed.

As best shown in Figs. 1,6, 7 and 8, the means for actuating-and controlling the, clutches 84 and 9 4, 95 and the brake band 93 comprisethe hand. lever; 41 rigidly arried by a rockvshaft I99 and 75 having; a link Hl-l' connecting it totheshitting yoke 89 whereby the collar 88 may be slid back and forth on the shaft 42 to engage and disengage the clutches 84 and 94, 95 as above described. The said rock-shaft also rigidly carries a pair of lost motion devices I02 and I03, the first of which is adapted to transmit motion in one direction to an arm I04 while the second is adapted to transmit motion in the opposite direction to an arm I05. The said arms are loosely mounted on the shaft I00, and the arm I04 is connected by linkage I06 to the brake band 93 whereby it may be released from its spring induced engagement with the drum 92. The arms I04 and I05 are connected respectively by links I01 and I08 with the opposite ends of a lever I09 pivoted at IIO to a bracket III carried by the machine frame.

In Fig. 6 the neutral position of the control lever 41 is shown in full lines, and when it is desired to elevate the skip 21 from the Fig. 3 to the Fig. 4 position, the lever 4! is moved clockwise (as viewed in Fig. 6) to the broken line position shown, which of course also moves the rock-shaft I in a like direction, This movement of the lever 41, through the linkage I 0|, moves the shifting yoke 89 to engage the clutch 84, but just prior to such engagement the lost motion device I02 picks up the arm I04 and moves it in a clockwise direction, which movement, through the linkage I06, releases the brake band 93 from the brake drum 92. Engagement of the clutch 84 thereupon drives shaft 42 and sprocket 90 of the transmission 45 in such direction as to cause chain 43, shaft 4| and chains 36 to raise the skip to the Fig. 4 position.

While the drive may be restored to neutral when the skip reaches this position through manual return of the lever 41 to the full line position of Fig. 4, for the sake of safety an automatic knock-out is preferably provided. As here shown, this comprises an arm 48 rigidly carried by the rock-shaft I 00, which arm is connected by a link 49 to a knock-out lever 50 (see Fig. 1) pivoted as at 5| on the machine frame. The free end of said lever 50 is positioned to be engaged and depressed by one of the upper skip rollers 3|, or an appropriate part of the skip frame, when the skip reaches the Fig. 4 position, whereby through the link 49 and arm 48 the shaft I00 and the parts carried thereby will be automatically returned to the neutral position.

With restoration of the parts to such position, the brake band 93 will be again applied to the drum 92 and the skip will be held in the elevated position; and incidentally, it may be so held at any point intermediate its upper and lower positions. To lower the skip the lever 41 is moved counterclockwise to the dotted line position of Fig. 6 which, through the linkage I 0| will move the shifting yoke 89 to bring the collar 88 into engagement with the abutment 96, 91 of shaft 42 and cause engagement of clutch elements 94 and 95. Just prior to such engagement the lost motion device I03 picks up the arm I05 to move it in a counterclockwise direction, which movement through linkage I08, I09 and I0! again moves the arm I94 clockwise to release the brake 93 through linkage I 06. The drive from the shaft 70 to the shaft 42 is now reversed and the sprocket 90, chain 43, shaft 4| and chains 36 are driven in such direction as draw the skip down should it tend to stick in the upper position. Also, continued engagement of the clutch elements 94 and 95 keeps the skip coupled to the drum during descent which, as above explained, controls and/or retards the downward movement.

As will be clear from Figs. 4 and 7, when the sub-chute 2| is drawn out to operative position it lies in the path of travel of portions of the skip structure, and if the skip be raised or lowered when the chute is in such position, damage to the chute will result. Therefore, means are provided to render it impossible to actuate the controls to effect raising or lowering of the skip when the sub-chute is in the said position. As is best shown in Figs, 6, 7 and 8, such means may take the form of a link 5 pivotally connected at 6 to the sub-chute 2|, and at II! to one arm of a bell-crank H8 mounted in brackets 9 carried by the frame. The other arm of said bell-crank is connected at I20 to one end of a link |2I, the other end of which is connected to a crank I22 also journaled on the frame and rigidly carrying a dog I23 which, in the raised or operative position of the sub-chute 2|, is disposed between the lever I09 and a member I0 of the frame. Since inward movement of the arm I 04either directly through the lost motion device I02, or indirectly through the device I03, arm I05, link I08, lever I09 and link |0'Iis necessary to release the brake 93 and since in either case such movement involves counterclockwise movement (as viewed in Fig. 8) of the lever I09, such interposition of the dog I23 between such lever and the frame member I0 when the sub-chute 2| is in its operative position, will prevent such actuation of said arm I04 and consequent release of the brake. However, when the sub-chute 2| is dropped to its inoperative position (shown in Figs. 3 and 4) the linkage H5, H8, I2I, I22 above described will raise the dog I23 out of the path of the lever I09, and the arm I04 may thereupon be actuated to release the brake.

The operation of the mechanism will be readily understood from the foregoing, it being understood that with the parts in the positions illustrated in Figs. 1 and 3, and the drum I3 rotating, upon engagement of the skip clutch and release of its brake through movement of the control lever 41 in one direction, power from the rotating drum I3 will be transmitted through drive 46, transmission 45, clutch 84, countershaft 42, drive 43 and shaft 4| to rotate the drive sprockets 40 in a counterclockwise direction, as viewed in Fig. 1. Such rotation of sprockets 40, through the chains 36, will elevate the skip with its batch of materials to the Fig. 4 position, the channels 25 serving as guiding tracks for the rollers 3| of the skip to keep it level during the first part of its travel, and then to tilt it to gravitationally discharge the materials during the latter part of the travel. In the course of its elevation and tilting, the plates 54 engage the projections 62 and draw out the apron 60, as above explained; and upon reaching the Fig. 4 position one of the rollers 3| (or some other appropriate portion of the skip structure) engages the knockout lever 50 which, through link 49 and connection 48, returns the control lever 41 to normal, thereby disengaging the clutch 84 and applying the brake to hold the skip in elevated position. When transfer of the materials from the skip to the drum has been completed, the lever 41 may be moved in the opposite direction, to release the brake and engage the clutch 94, 95 whereupon the skip will be lowered at a substantially uniform rate controlled by the drum I3, to its Fig. 3 position for the reception of another batch of materials.

accrues The mixer may be operated in accordance with the usual truck-mixer practice, i. e. with the drum [3 rotating in one direction to mix and in the opposite direction for discharge; or, since the chute 59 will prevent unintentional discharge, the machine may be uni-directionally operated in accordance with the principles disclosed in prior U. S. Patent No. 2,303,902 granted December l, 1942, on an application filed by Charles F. Ball. In either case, for discharge of the mixed concrete from the drum, the chute 59 is swun away from the drip ring 19, to substantially the broken line position shown in Fig. 4, by manually moving the lever 51 from the full line to the broken line position shown in Fig. 1. A notched plate 66, or other appropriate detent, may be provided for co-operation with the lever 51, to retain it in either of its positions.

While one form of the invention has been 11- lustrated and described, it will be readily apparent that those skilled in the art may vary the details of construction as well as the precise arrangement of parts without departing from the spirit of the invention, and therefore it is not wished to be limited to the above disclosure except as may be required by the claims.

What is claimed is:

1. In a concrete mixer having a rotatable mixing drum provided at one end with a materialtransfer opening: a skip for receiving batches of concrete-making materials for transfer into said drum; means for elevating the skip to adjacent the drum opening for discharge of the skip contents thereto; a chute extending from said opening to a point spaced from the skip in its discharge position, for guiding the materials from the skip to the opening; a movable apron for bridging the gap between the skip and chute sufficiently to prevent spilling of the materials through said gap during transfer, said apron being normally disposed in a position to clear the skip in the raising and lowering movements of the latter; and means for moving the apron from such position to its gap-bridging position as the skip approaches its discharge position.

2. A concrete mixer according to claim 1, wherein the apron is normally telescoped within the chute, and is provided with means engageable by the skip to move the apron to operative position as the skip approaches its discharge position.

3. A concrete mixer according to claim 1, wherein the apron is normally telescoped within the chute to permit passage of the skip, and is provided with projections engageable by skipoarried members as the skip approaches its discharge position, whereby the apron is automaticaily withdrawn from the chute into operative Position 4. In a concrete mixer having a mixing drum provided with a material-transfer opening, and a. charging skip movable to and from a co-operative position relative to said opening: a chute member mounted adjacent said opening for movement to and from a position in which it lies in the path of travel of said skip; and means controlled by said chute member for preventing movements of said skip when the chute member is in said position.

5. In a concrete mixer having a mixing drum provided with a material-transfer opening, a charging skip mounted for movement to and from a position adjacent said opening, means for so moving said skip, and means for controlling said moving means: a. chute member mounted adjacent said opening for movement to and from a position in which a portion thereof is in the path or travel of the skip; and connections between said chute member and controlling means for preventing actuation of the latter to instigate movements of the skip when the chute member is in said interfering position.

6. In a concrete mixer having a mixing drum provided with a material-transfer opening, a charging skip mounted for movement to and from a position adjacent said opening, means for so moving said skip, and means for controlling said moving means: a chute member mounted adjacent said opening for movement to and from a position in which a portion thereof is in the path of travel of the skip; a dog mounted for movement to and from a position in which it may prevent actuation of said controlling means; and linkage connecting said dog and chute member, whereby movement of the latter to its interferin position moves the dog to its operative position.

LOUIS G. HILKEMEIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 973,543 Muller Oct. 25, 1910 1,523,548 Lichtenberg Jan. 20, 1925 1,662,274 Koehring Mar. 13, 1928 1,760,101 Yohe May 27, 1930 1,761,801 Robb June 3, 1930 2,180,469 Jaeger et a1. Nov. 21, 1939 2,323,753 Jaeger et a1 July 6, 1943 FOREIGN PATENTS Number Country Date 440,217 Germany Feb. 1, 1927 

